question_answer

An open knife edge of mass M is dropped from a height h on a wooden floor. If the blade penetrates S into the wood, the average resistance offered by the wood to the blade is

A)  \[Mg\]                

B)         \[Mg\left( 1+\frac{h}{S} \right)\]

C)  \[Mg(1+hS)\]   

D)         \[mg{{\left( 1+\frac{h}{S} \right)}^{2}}\]

E)        None of these